A. Field of the Invention
The present invention relates to flush valves that control the outflow of water from a toilet tank. It is especially useful in connection with "one piece" toilets that are constructed so that there is no easy way to reach the underside of the bottom wall of the tank after the toilet has been manufactured.
B. Description of the Art
A well-known type of toilet is one in which the water storage tank and toilet bowl are formed in two separate pieces. Such toilets often have a washer placed around an outlet formed in the bottom of the tank, and a valve housing mounted on the washer and through the washer and outlet. To insure that the housing is fixed in this position, the housing is usually formed with a threaded lower end that extends below the tank bottom wall. A nut is provided which is suitable to be screwed onto these threads (from below the tank wall), so that the nut abuts against the underside of the tank bottom wall. While this flush valve assembly has proved generally satisfactory for "two piece" toilets, the plumbing industry is always interested in ways to further reduce the amount of time required for installation.
Another type of known toilet is the "one piece" toilet. For many one piece toilets, the underside of the tank bottom wall is not accessible. This is because a channel from the tank to the toilet bowl and/or a toilet siphon leg is cast directly underneath the tank.
For such toilets, it is very difficult to attach a conventional flush valve to the "blind hole" at the bottom of the tank. (When there is no easy way to reach the underside of the tank bottom wall, it is very difficult to position a nut under the bottom wall, and then thread it onto an end of the valve housing which is below the tank wall.)
The plumbing industry has therefore attempted to develop flush valve attachment systems which are more suitable for blind outlet holes. Such prior art assemblies have required the use of complicated tools, web structures in the path of flow, and/or the use of glues or soldering. These assemblies are not satisfactory because in order to maximize the cleaning effect of the water, the flush valve should not interfere with the flow through an open outlet. Further, the cost of production and installation of these assemblies is high. Also, assemblies of this type often cannot be installed by consumers who do not have expertise in the plumbing field.